Terminal apparatus, base station apparatus, integrated circuit, and communication method

ABSTRACT

A terminal apparatus includes a reception unit that receives first information indicating a subframe in which a CRS is present, and second information which indicates the number of CRS antenna ports and is used to determine a resource element to which a PDSCH is mapped. In a subframe other than a subframe indicated as the subframe in which the CRS is present by the first information, a resource element to which a PDSCH transmitted through an antenna port different from a CRS antenna port for a serving cell is mapped is based on the number of CRS antenna ports indicated by the second information corresponding to the PDSCH. Accordingly, the terminal apparatus can efficiently communicate with a base station apparatus using a downlink physical channel.

TECHNICAL FIELD

The present invention relates to a terminal apparatus, a base stationapparatus, an integrated circuit, and a communication method.

The present application claims priority to Japanese Patent ApplicationNo. 2013-145349 filed in the Japanese Patent Office on Jul. 11, 2013,the disclosure of which is herein incorporated by reference in itsentirety.

BACKGROUND ART

A cellular mobile communication wireless access system and a wirelessnetwork (hereinafter, referred to as “Long Term Evolution (LTE)” or“Evolved Universal Terrestrial Radio Access (EUTRA)”) have been examinedin the 3rd Generation Partnership Project (3GPP). In the LTE system, abase station apparatus is also referred to as evolved NodeB (eNodeB) anda terminal apparatus is also referred to as user equipment (UE). The LTEsystem is a cellular communication system in which a plurality ofcoverage areas of the base station apparatus is arranged in a cellshape. A single base station apparatus may manage a plurality of cells.

The base station apparatus transmits data to the terminal apparatususing a physical downlink shared channel (PDSCH). In the 3GPP, thesupport for coordinated multi-point transmission and reception (CoMP)which is a technology in which a plurality of base station apparatuses(cells, transmission points, or reception points) is coordinated witheach other to perform interference coordination has been examined. Thebase station apparatus can transmit a single PDSCH to the terminalapparatus by using one of the plurality of coordinated transmissionpoints. The base station apparatus can transmit a single PDSCH to theterminal apparatus by using the plurality of coordinated transmissionpoints.

NPL 1 describes a technology of controlling the transmission power of aPDSCH for each transmission point in the CoMP. In NPL 1, a parameter(P_(B)) related to the transmission power of the PDSCH is correlatedwith a DMRS virtual cell ID. NPL 1 describes that the parameter (P_(B))corresponds to a power boosting level for a cell-specific referencesignal (CRS).

CITATION LIST Non Patent Document

-   [Non Patent Document 1]“Further discussion on downlink power    allocation for CoMP”, R1-123478, 3GPP TSG-RAN WG1 Meeting #70, 13-17    Aug. 2012.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

For example, in the technology described in NPL 1, there is a problemthat it is difficult to control a power of a PDSCH for each OFDM symbolin each transmission point. An aspect of the present invention is toprovide a terminal apparatus, a base station apparatus, an integratedcircuit, and a communication method which are capable of efficientlyperforming communication using a downlink physical channel.

Means for Solving the Problems

(1) In order to achieve the aforementioned object, the present inventionprovides the following means. That is, according to an aspect of thepresent invention, there is provided a terminal apparatus thatcommunicates with a base station apparatus. The terminal apparatusincludes: a reception unit that receives first information indicating asubframe in which a cell-specific reference signal (CRS) is present, andsecond information which indicates the number of CRS antenna ports andis used to determine a resource element to which a physical downlinkcontrol channel (PDSCH) is mapped. In a subframe other than a subframeindicated as the subframe in which the CRS is present by the firstinformation, a resource element to which a PDSCH transmitted through anantenna port different from a CRS antenna port for a serving cell ismapped is based on the number of CRS antenna ports indicated by thesecond information corresponding to the PDSCH.

(2) According to an aspect of the present invention, there is provided acommunication method used in a terminal apparatus that communicates witha base station apparatus. The communication method includes: receivingfirst information indicating a subframe in which a cell-specificreference signal (CRS) is present, and second information whichindicates the number of CRS antenna ports and is used to determine aresource element to which a physical downlink control channel (PDSCH) ismapped. In a subframe other than a subframe indicated as the subframe inwhich the CRS is present by the first information, a resource element towhich a PDSCH transmitted through an antenna port different from a CRSantenna port for a serving cell is mapped is based on the number of CRSantenna ports indicated by the second information corresponding to thePDSCH.

(3) According to an aspect of the present invention, there is providedan integrated circuit used in a terminal apparatus that communicateswith a base station apparatus. The integrated circuit causes theterminal apparatus to exhibit a series of functions including a functionof receiving first information indicating a subframe in which acell-specific reference signal (CRS) is present, and second informationwhich indicates the number of CRS antenna ports and is used to determinea resource element to which a physical downlink control channel (PDSCH)is mapped. In a subframe other than a subframe indicated as the subframein which the CRS is present by the first information, a resource elementto which a PDSCH transmitted through an antenna port different from aCRS antenna port for a serving cell is mapped is based on the number ofCRS antenna ports indicated by the second information corresponding tothe PDSCH.

(4) According to an aspect of the present invention, there is provided abase station apparatus that communicates with a terminal apparatus. Thebase station apparatus includes: a transmission unit that transmitsfirst information indicating a subframe in which a cell-specificreference signal (CRS) is present, and second information whichindicates the number of CRS antenna ports and is used to determine aresource element to which a physical downlink control channel (PDSCH) ismapped. In a subframe other than a subframe indicated as the subframe inwhich the CRS is present by the first information, a resource element towhich a PDSCH transmitted through an antenna port different from a CRSantenna port for a serving cell is mapped is based on the number of CRSantenna ports indicated by the second information corresponding to thePDSCH.

(5) According to an aspect of the present invention, there is provided acommunication method used in a base station apparatus that communicateswith a terminal apparatus. The communication method includes:transmitting first information indicating a subframe in which acell-specific reference signal (CRS) is present, and second informationwhich indicates the number of CRS antenna ports and is used to determinea resource element to which a physical downlink control channel (PDSCH)is mapped. In a subframe other than a subframe indicated as the subframein which the CRS is present by the first information, a resource elementto which a PDSCH transmitted through an antenna port different from aCRS antenna port for a serving cell is mapped is based on the number ofCRS antenna ports indicated by the second information corresponding tothe PDSCH.

(6) According to an aspect of the present invention, there is providedan integrated circuit used in a base station apparatus that communicateswith a terminal apparatus. The integrated circuit causes the basestation apparatus to exhibit a series of functions including a functionof transmitting first information indicating a subframe in which acell-specific reference signal (CRS) is present, and second informationwhich indicates the number of CRS antenna ports and is used to determinea resource element to which a physical downlink control channel (PDSCH)is mapped. In a subframe other than a subframe indicated as the subframein which the CRS is present by the first information, a resource elementto which a PDSCH transmitted through an antenna port different from aCRS antenna port for a serving cell is mapped is based on the number ofCRS antenna ports indicated by the second information corresponding tothe PDSCH.

Effects of the Invention

According to the aspect of the present invention, a terminal apparatusand a base station apparatus can efficiently communicate using adownlink physical channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram of a wireless communication systemaccording to the present embodiment.

FIG. 2 is a diagram showing a schematic structure of a radio frameaccording to the present embodiment.

FIG. 3 is a diagram showing the structure of a slot according to thepresent embodiment.

FIG. 4 is a diagram showing an example of the arrangement of physicalchannels and physical signals in a subframe of a downlink according tothe present embodiment.

FIG. 5 is a diagram showing an example of the arrangement of physicalchannels and physical signals in a subframe of an uplink according tothe present embodiment.

FIG. 6 is a diagram showing the arrangement of CRSs and URSs in anon-MBSFN subframe according to the present embodiment.

FIG. 7 is a diagram showing the arrangement of CRSs and URSs in a MBSFNsubframe according to the present embodiment.

FIG. 8 is a table showing the correspondence of a parameter set with avalue of a PQI field according to the present embodiment.

FIG. 9 is a table showing a third ratio (ρ_(B)/ρ_(A)) according to thepresent embodiment.

FIG. 10 is a table showing an OFDM symbol index within the slot of thenon-MBSFN subframe, in which a ratio of corresponding PDSCH EPRE to CRSEPRE of a serving cell is expressed by ρ_(A) or ρ_(B) according to thepresent embodiment.

FIG. 11 is a table showing an OFDM symbol index within the slot of theMBSFN subframe, in which a ratio of corresponding PDSCH EPRE to CRS EPREof a serving cell is expressed by ρ_(A) or ρ_(B) according to thepresent embodiment.

FIG. 12 is a diagram showing an example of the OFDM symbol indexcorresponding to the ρ_(A) or ρ_(B) according to the present embodiment.

FIG. 13 is a diagram showing another example of the OFDM symbol indexcorresponding to the ρ_(A) or ρ_(B) according to the present embodiment.

FIG. 14 is a schematic block diagram showing the structure of a terminalapparatus 1 according to the present embodiment.

FIG. 15 is a schematic block diagram showing the structure of a basestation apparatus 3 according to the present embodiment.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described.

In the present embodiment, a plurality of cells is configured for aterminal apparatus. A technology in which the terminal apparatusperforms communication through the plurality of cells is referred to ascell aggregation or carrier aggregation. The present invention may beapplied to each of the plurality of cells configured for the terminalapparatus. The present invention may be applied to some of the pluralityof configured cells. The cell configured for the terminal apparatus isalso referred to as serving cell.

The plurality of configured serving cells includes one primary cell, andone secondary cell or a plurality of secondary cells. The primary cellis a serving cell in which an initial connection establishment procedureis performed, a serving cell in which a connection re-establishmentprocedure is started, or a cell indicated as the primary cell in ahandover procedure. The secondary cell may be configured at a point oftime when RRC connection is established or after the RRC connection isestablished.

In the case of the cell aggregation, a TDD (Time Division Duplex) systemor a FDD (Frequency Division Duplex) system may be applied to all theplurality of cells. In the case of the cell aggregation, cells to whichthe TDD system is applied and cells to which the FDD system is appliedmay be aggregated. In the present embodiment, although it will bedescribed that the cells to which the FDD is applied are used, thepresent invention may be applied to the cells to which the TDD isapplied.

FIG. 1 is a conceptual diagram showing a wireless communication systemaccording to the present embodiment. In FIG. 1, the wirelesscommunication system includes terminal apparatuses 1A to 1C, and a basestation apparatus 3. Hereinafter, the terminal apparatuses 1A to 1C arereferred to as the terminal apparatus 1. In FIG. 1, the base stationapparatus 3 includes a first transmission and reception point, and asecond transmission and reception point. The base station apparatus 3can transmit a signal in the first transmission and reception pointand/or the second transmission and reception point. The base stationapparatus 3 can receive a signal in the first transmission and receptionpoint and/or the second transmission and reception point.

An area covered by the first transmission point is referred to as afirst cell. An area covered by the second transmission point is referredto as a second cell. In FIG. 1, the first cell is a serving cell and thesecond cell is a coordinated cell for the terminal apparatuses 1A to 1C.The serving cell is non-transparent for the terminal apparatus 1. Thecoordinated cell may be transparent for the terminal apparatus 1. Thefirst cell may be a coordinated cell, and the second cell may be aserving cell for the terminal apparatus 1. The first cell and the secondcell are constructed in the same frequency band.

Physical channels and physical signals according to the presentembodiment will be described.

A downlink physical channel and a downlink physical signal arecollectively referred to as downlink signals. An uplink physical channeland an uplink physical signal are collectively referred to as uplinksignal. The downlink physical channel and the uplink physical channelare collectively referred to as physical channel. The downlink physicalsignal and the uplink physical signal are collectively referred to asphysical signal. The physical channel is used to transmit informationoutput from a higher layer. The physical signal is not used to transmitthe information output from the higher layer, but is used by a physicallayer.

In FIG. 1, in uplink wireless communication from the terminal apparatus1 to the base station apparatus 3, the following uplink physicalchannels are used.

-   -   Physical uplink control channel (PUCCH)    -   Physical uplink shared channel (PUSCH)    -   Physical random access channel (PRACH)

The PUCCH is a physical channel used to transmit uplink controlinformation (UCI). The uplink control information includes channel stateinformation (CSI) of a downlink, a scheduling request (SR) indicating arequest for a PUSCH resource, and acknowledgement (ACK) andnegative-acknowledgement ACK (NACK) in response to downlink data (TB:transport block, DL-SCH: Downlink-Shared channel). The ACK/NACK isreferred to as HARQ-ACK or HARQ feedback.

The PUSCH is a physical channel used to transmit uplink data (UL-SCH:Uplink-Shared Channel) and/or the HARQ-ACK and/or the channel stateinformation.

The PRACH is a physical channel used to transmit a random accesspreamble. The PRACH is used in an initial connection establishmentprocedure, a handover procedure, and a connection re-establishmentprocedure.

In FIG. 1, in the uplink wireless communication, the following uplinkphysical signals are used.

-   -   Uplink reference signal (UL RS)

In the present embodiment, the following two types of uplink referencesignals are used.

-   -   Demodulation reference signal (DMRS)    -   Sounding reference signal (SRS)

The DMRS is related to the transmission of the PUSCH or the PUCCH. TheDMRS is time-multiplexed with the PUSCH or the PUCCH. The base stationapparatus 3 uses the DMRS in order to correct the channel of the PUSCHor the PUCCH. Hereinafter, the simultaneous transmission of the PUSCHand the DMRS is simply referred to as the transmission of the PUSCH.Hereinafter, the simultaneous transmission of the PUCCH and the DMRS issimply referred to as the transmission of the PUCCH. The SRS is notrelated to the transmission of the PUSCH or the PUCCH. The base stationapparatus 3 uses the SRS in order to measure a channel state of theuplink.

In FIG. 1, in downlink wireless communication from the base stationapparatus 3 to the terminal apparatus 1, the following downlink physicalchannels are used.

-   -   Physical broadcast channel (PBCH)    -   Physical control format indicator channel (PCFICH)    -   Physical hybrid automatic repeat request indicator channel        (PHICH)    -   Physical downlink control channel (PDCCH)    -   Enhanced physical downlink control channel (EPDCCH)    -   PDSCH (Physical Downlink Shared channel)    -   Physical multicast channel (PMCH)

The PBCH is used to broadcast a master information block (MIB, broadcastchannel (BCH)) which is shared by the terminal apparatuses 1. The MIB istransmitted at an interval of 40 ms. The MIB is repeatedly transmittedwith a period of 10 ms. For example, the MIB includes informationindicating SFN. The SFN (System Frame Number) is a radio frame number.The MIB is system information.

The PCFICH is used to transmit information indicating a region (OFDMsymbols) which is used to transmit the PDCCH.

The PHICH is used to transmit a HARQ indicator (HARQ feedback) whichindicates acknowledgement (ACK) or negative acknowledgement (NACK) ofuplink data (uplink shared channel: UL-SCH) received by the base stationapparatus 3.

The PDCCH and the EPDCCH are used to transmit downlink controlinformation (DCI). The downlink control information is referred to as aDCI format. The downlink control information includes a downlink grantand an uplink grant. The downlink grant is referred to as downlinkassignment or downlink allocation.

The uplink grant is used to schedule a single PUSCH in a single cell.The uplink grant is used to schedule a single PUSCH in a given subframe.

The downlink grant is used to schedule a single PDSCH in a single cell.The downlink grant is used to schedule the PDSCH in the same subframe asa subframe in which the downlink grant is transmitted. The downlinkgrant includes a DCT format 1A and a DCI format 2D. The DCI format 1Adoes not include a PQI (PDSCH RE Mapping and Quasi-Co-LocationIndicator) field. The DCI format 2D include the PQI field.

The terminal apparatus 1 set in transmission mode 10 monitors the PDCCHand/or the EPDCCH for the DCI format 1A and the DCI format 2D. Themonitoring means that the decoding (receiving or detecting) of the PDCCHand/or the EPDCCH according to all the monitored DCI formats is tried.The transmission mode is controlled for each serving cell by the basestation apparatus 3. The terminal apparatus 3 sets the transmission modeto the serving cell based on a higher layer signal received from thebase station apparatus 3. That is, the base station apparatus 3 sets thetransmission mode to the terminal apparatus 1 by using the higher layersignal.

A cyclic redundancy check (CRC) parity bit is added to the DCI format.The CRC parity bit is scrambled by a cell-radio network temporaryidentifier (C-RNTI) or a semi persistent scheduling cell-radio networktemporary identifier (SPS C-RNTI). The C-RNTI and the SPS C-RNTI areidentifiers for identifying the terminal apparatuses 1 in the cell. TheC-RNTI is used to control resources of the PDSCH or resources of thePUSCH in a single subframe. The SPS C-RNTI is used to periodicallyallocate the resources of the PDSCH or PUSCH.

The PDSCH is used to transmit downlink data (downlink shared channel:DL-SCH).

The PMCH is used to transmit multicast data (multicast channel: MCH).

In FIG. 1, in the downlink wireless communication, the followingdownlink physical signals are used.

-   -   Synchronization signal (SS)    -   Downlink reference signal (DL RS)

The synchronization signals are used to allow the terminal apparatus 1to be synchronized in the frequency domain and the time domain of thedownlink. In the FDD system, the synchronization signals are arranged insubframes 0 and 5 of the radio frame.

The downlink reference signal is used to correct the channel of thedownlink physical channel by the terminal apparatus 1. The downlinkreference signal is used to calculate the channel state information ofthe downlink by the terminal apparatus 1. The downlink reference signalis used to measure a geographic location of the terminal apparatus bythe terminal apparatus 1.

In the present embodiment, the following five types of downlinkreference signals are used.

-   -   Cell-specific reference signal (CRS)    -   UE-specific reference signal (URS) related to PDSCH    -   Demodulation reference signal (DMRS) related to EPDCCH    -   Non-zero power channel state information-reference signal (NZP        CSI-RS)    -   Zero power channel state information-reference signal (ZP        CSI-RS)    -   Multimedia broadcast and multicast service over single frequency        network reference signal (MBSFN RS)

The CRS is transmitted in all bands of the subframe. The CRS is used todemodulate the PBCH/PDCCH/PHICH/PCFICH/and the PDSCH. The CRS may beused to calculate the channel state information of the downlink by theterminal apparatus 1. The PBCH/PDCCH/PHICH/and the PCFICH aretransmitted through an antenna port which is used to transmit the CRS.

The CRS of the serving cell is transmitted in the same set as that ofthe antenna port used to transmit the PBCH of the serving cell (firsttransmission point). The PBCH is transmitted in antenna ports {0}, {0,1} or {0, 1, 2, 3}. Hereinafter, the antenna ports {0}, {0, 1} and {0,1, 2, 3} are referred to as a cell specific antenna port, a CRS antennaport, or an antenna port 0-3. Particularly, the antenna port used totransmit the PBCH of the serving cell and the CRS of the serving cell isreferred to as a CRS antenna port for the serving cell, a CRS antennaport in the serving cell, or a CRS antenna port of the serving cell.

The URS related to the PDSCH is transmitted in a subframe and a bandthat are used to transmit the PDSCH to which the URS is related. The URSis used to demodulate the PDSCH to which the URS is related. The PDSCHis transmitted through the antenna port used to transmit the CRS or theantenna port used to transmit the URS. The URS is transmitted throughone antenna port or a plurality of antenna ports {7, 8, . . . , 14}.Hereinafter, one antenna port or the plurality of antenna ports {7, 8, .. . , 14} is referred to as a URS antenna port or antenna ports 7 to 14.

The URS related to the PDSCH and the PDSCH transmitted through the URSantenna port may be transparent for the terminal apparatus 1. That is,it is difficult for the terminal apparatus 1 to specify the serving cellor the coordinated cell in which the URS related to the PDSCH and thePDSCH transmitted through the URS antenna port are transmitted. Theterminal apparatus 1 may not specify the transmission point in which theURS related to the PDSCH and the PDSCH transmitted through the URSantenna port are transmitted. The URS transmitted in the firsttransmission point, the second transmission point, the serving cell orthe coordinated cell and the URS antenna port through which the URS istransmitted are respectively referred to as an URS in the serving celland an URS antenna port in the serving cell. The PDSCH transmittedthrough the URS antenna port in the first transmission point, the secondtransmission point, the serving cell or the coordinated cell is alsoreferred to as an URS antenna port for the serving cell, a PDSCH in theserving cell, and a PDSCH of the serving cell.

The DMRS related to the EPDCCH is transmitted in a subframe and a bandthat are used to transmit the EPDCCH to which the DMRS is related. TheDMRS is used to demodulate the EPDCCH to which the DMRS is related. TheEPDCCH is transmitted through an antenna port which is used to transmitthe DMRS.

The NZP CSI-RS is transmitted in the configured subframe. Resources inwhich the NZP CSI-RS is transmitted are configured by the base stationapparatus 3. The NZP CSI-RS is used to calculate the channel stateinformation of the downlink by the terminal apparatus 1. The terminalapparatus 1 performs signal measurement (channel measurement) by usingthe NZP CSI-RS.

The resources of the ZP CSI-RS are configured by the base stationapparatus 3. The base station apparatus 3 transmits the ZP CSI-RS withzero output. That is, the base station apparatus 3 does not transmit theZP CSI-RS. The base station apparatus 3 does not transmit the PDSCH andthe EPDCCH in the configured resources of the ZP CSI-RS.

For example, the terminal apparatus 1 can measure interference inresources corresponding to the NZP CSI-RS in a given cell.

The MBSFN RS is transmitted in all bands of the subframe used totransmit the PMCH. The MBSFN RS is used to demodulate the PMCH. The PMCHis transmitted through an antenna port that is used to transmit theMBSFN RS.

The BCH, the MCH, the UL-SCH, and the DL-SCH are transport channels. Thechannel which is used in a medium access control (MAC) layer is referredto as a transport channel. The unit of data in the transport channelused in the MAC layer is also referred to as a transport block (TB) or aMAC protocol data unit (PDU). Hybrid automatic repeat request (HARQ)control is performed for each transport block in the MAC layer. Thetransport block is the unit of data which is transmitted (delivered) bythe MAC layer to the physical layer. In the physical layer, thetransport block is mapped to a code word and a coding process isperformed for each code word.

Hereinafter, the structure of the radio frame of present embodiment willbe described.

FIG. 2 is a diagram showing a schematic structure of the radio frameaccording to the present embodiment. Each radio frame has a length of 10ms. In FIG. 2, a horizontal axis represents a time axis, and is definedby 10 subframes. Each subframe has a length of 1 ms, and is defined bytwo consecutive slots. Each slot has a length of 0.5 ms. An i-thsubframe in the radio frame includes a (2×i)-th slot and a (2×i+1)-thslot.

Hereinafter, the structure of the slot according to the presentembodiment will be described.

FIG. 3 is a diagram showing the structure of the slot according to thepresent embodiment. In the present embodiment, a normal cyclic prefix(CP) is applied to OFDM symbols. An extended CP may be applied to theOFDM symbols. The physical signals or the physical channels transmittedin the respective slots are represented by resource grids. In FIG. 3, ahorizontal axis represents a time axis, and a vertical axis represents afrequency axis. In the downlink, a resource grid is defined by aplurality of subcarriers and a plurality of OFDM symbols. In the uplink,a resource grid is defined by a plurality of subcarriers and a pluralityof SC-FDMA symbols. The number of subcarriers constituting one slotdepends on a bandwidth of the cell. The number of OFDM symbols orSC-FDMA symbols constituting one slot is seven. Each element in theresource grid is referred to as a resource element. The resource elementis identified using a subcarrier number and an OFDM symbol number or aSC-FDMA symbol number.

The resource block is used to represent the mapping of a given physicalchannel (for example, the PDSCH or the PUSCH) to the resource element.For the resource block, a virtual resource block and a physical resourceblock are defined. Initially, a given physical channel is mapped to thevirtual resource block. Thereafter, the virtual resource block is mappedto the physical resource block. One physical resource block is definedby 7 consecutive OFDM symbols or SC-FDMA symbols in the time domain and12 consecutive subcarriers in the frequency domain. Therefore, onephysical resource block includes (7×12) resource elements. In addition,one physical resource block corresponds to one slot in the time domainand corresponds to 180 kHz in the frequency domain. The physicalresource block is numbered from 0 in the frequency domain.

Hereinafter, the physical channels and the physical signals which aretransmitted in each subframe will be described.

FIG. 4 is a diagram showing an example of the arrangement of thephysical channels and the physical signals in the downlink subframeaccording to the present embodiment. In FIG. 4, a horizontal axisrepresents a time axis, and a vertical axis represents a frequency axis.The base station apparatus 3 may transmit the downlink physical channels(PBCH, PCFICH, PHICH, PDCCH, EPDCCH and PDSCH) and the downlink physicalsignals (synchronization signals and downlink reference signals) in thedownlink subframe. The PBCH is transmitted in only the subframe 0 of theradio frame. For the sake of convenience in description, the downlinkreference signals are not shown in FIG. 4. The arrangement of the CRSsand the URSs will be described below.

In a PDCCH region, frequency multiplexing and time multiplexing may beperformed on a plurality of PDCCHs. In an EPDCCH region, frequencymultiplexing, time multiplexing, and spatial multiplexing may beperformed on a plurality of EPDCCHs. In a PDSCH region, frequencymultiplexing and spatial multiplexing may be performed on a plurality ofPDSCHs. Time multiplexing may be performed on the PDCCH and the PDSCH orthe EPDCCH. Frequency multiplexing may be performed on the PDSCH and theEPDCCH.

The downlink subframe includes a multicast broadcast single frequencynetwork (MBSFN) subframe, and a non-MBSFN subframe. The PMCH istransmitted in only the MBSFN subframe. The PBCH, PCFICH, PHICH, PDCCH,EPDCCH and PDSCH are transmitted in the MBSFN subframe and the non-MBSFNsubframe. The PMCH and the PDSCH are not simultaneously transmitted inone MBSFN subframe in a given serving cell.

The base station apparatus 3 transmits a higher layer signal includinginformation indicating the MBSFN subframe and the non-MBSFN subframe inthe serving cell to the terminal apparatus 1. The terminal apparatus 1sets parameter mbsfn-SubframeConfigList indicating the MBSFN subframeand the non-MBSFN subframe in the serving cell based on the higher layersignal received from the base station apparatus 3. That is, the basestation apparatus 3 sets the parameter mbsfn-SubframeConfigListindicating the MBSFN subframe and the non-MBSFN subframe in the servingcell to the terminal apparatus 1 by using the higher layer signal.

Here, the terminal apparatus 1 may regard a subframe that is notindicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList as the non-MBSFN subframe. For example, theparameter of mbsfn-SubframeConfigList may not indicate the subframe 0and the subframe 5 as the MBSFN subframe. That is, the subframe 0 andthe subframe 5 may be constantly the non-MB SFN subframe.

FIG. 5 is a diagram showing an example of the arrangement of thephysical channels and the physical signals in the uplink subframeaccording to the present embodiment. In FIG. 5, a horizontal axis is atime axis, and a vertical axis is a frequency axis. The terminalapparatus 1 may transmit the uplink physical channels (PUCCH, PUSCH andPRACH) and the uplink physical signals (DMRS and SRS) in the uplinksubframe. In a PUCCH region, frequency multiplexing, time multiplexingand code multiplexing are performed on a plurality of PUCCHs. In a PUSCHregion, frequency multiplexing and spatial multiplexing may be performedon a plurality of PUSCHs. Frequency multiplexing may be performed on thePUCCH and the PUSCH. The PRACHs may be arranged in a single subframe orover two subframes. Code multiplexing may be performed on the pluralityof PRACHs.

The SRS is transmitted using the last SC-FDMA symbol in the uplinksubframe. That is, the SRS is arranged in the last SC-FDMA symbol of theuplink subframe. The DMRS is time-multiplexed with the PUCCH or thePUSCH. For simplicity of illustration, the DMRS is not shown in FIG. 5.

Hereinafter, the arrangement of the CRSs and the URSs will be described.

FIG. 6 is a diagram showing the arrangement of the CRSs and the URSs inthe non-MBSFN subframe according to the present embodiment. FIG. 7 is adiagram showing the arrangement of the CRSs and the URSs in the MBSFNsubframe according to the present embodiment. In FIGS. 6 and 7, ahorizontal axis represents a time axis, and a vertical axis represents afrequency axis. In FIGS. 6 and 7, one subframe is shown in the timedomain, and a bandwidth of one physical resource block is shown in thefrequency domain. FIGS. 6 and 7 show examples in a case where the numberof CRS antenna ports is 4 and the number of URS antenna ports is 8.

In FIGS. 6 and 7, squares to which Ri (i=0, 1, 2 and 3) is assignedindicate resource elements to which the CRSs transmitted through the CRSantenna port i are mapped. In FIGS. 6 and 7, squares to which U7 isassigned indicate resource elements to which the URSs transmittedthrough URS antenna ports {7, 8, 11 13} are mapped, and squares to whichU9 is assigned indicate resource elements to which the URSs transmittedthrough URS antenna ports {9, 10, 12, 14} are mapped. The codemultiplexing is performed on the URSs transmitted through the URSantenna ports {7, 8, 11, 13}. The code multiplexing is performed on theURSs transmitted through the URS antenna ports {9, 10, 12, 14}.

In FIGS. 6 and 7, the PDSCHs may be transmitted in resource elements towhich the CRSs and the URSs are not mapped. In FIGS. 6 and 7, in a casewhere the CRS antenna port is {0}, the PDSCHs may be transmitted in theresource elements to which the R1, R2 and R3 are assigned. In FIGS. 6and 7, in a case where the CRS antenna port is {0, 1}, the PDSCHs may betransmitted in the resource elements to which the R2 and R3 areassigned. In FIGS. 6 and 7, in a case where the URS antenna port is {7},{8} or {7, 8}, the PDSCHs may be transmitted in the resource elements towhich the U9 is assigned.

The CRSs may not be present in a part or all of the subframes of a givenserving cell. The base station apparatus 3 may control whether or not totransmit the CRSs in the subframe. The base station apparatus 3 maytransmit information/parameter noCRS-SubframeConfig-r12 indicatingsubframes (subframe sets) in which the CRS is not present to theterminal apparatus 1. The base station apparatus 3 may transmitinformation/parameter noCRS-servcellConfig-r12 indicating that the CRSis not present in the serving cell to the terminal apparatus 1. The basestation apparatus 3 may transmit information/parameter SubframeSetConfigindicating a plurality of subframe sets andinformation/noCRS-SubframeSetConfig-r12 indicating whether or not theCRS is present in each of the plurality of subframe sets to the terminalapparatus 1. The parameter noCRS-SubframeConfig-r12, the parameternoCRS-servcellConfig-r12, and a set of the parameterSubframeSetConfig-r12 and the parameter noCRS-SubframeSetConfig-r12 isalso referred to as parameter noCRS-Config-r12.

A subframe indicated as the serving cell in which the CRS is not presentbased on the parameter noCRS-Config-r12 is referred to as a noCRSsubframe, a subframe in which the CRS is not transmitted, or a subframein which the CRS is not present. A subframe other than the noCRSsubframe is referred to as a CRS subframe, a subframe in which the CRSis transmitted, or a subframe in which the CRS is present. In FIGS. 6and 7, in the subframe in which the CRS is not present, the PDSCHs maybe transmitted in the resource elements to which the R0, R1, R2 and R3are assigned.

The resource elements to which the CRSs are mapped may be shifted in thefrequency domain. The shift in the frequency domain is referred to asfrequency shift. In FIGS. 6 and 7, the shift in the frequency domain is0. A value of the frequency shift of the CRS for the serving cell isdetermined based on a physical layer cell identity (PCI) for the servingcell. That is, the position of the CRS in a given subframe is determinedbased on the number of CRS antenna ports, a value of the frequencyshift, whether or not the subframe is indicated as the MBSFN subframe,and/or whether or not the subframe is indicated as the subframe in whichthe CRS is not present.

In the resource block in which the URS is not transmitted, the PDSCH istransmitted through the CRS antenna port. In the resource block in whichthe URS is transmitted, the PDSCH is transmitted through the URS antennaport. In a case where the PDSCH is transmitted in the MBSFN subframe,the PDSCH is transmitted through the URS antenna port. In a case wherethe PDSCH is transmitted in the noCRS subframe, the PDSCH is transmittedthrough the URS antenna port.

For example, in a case where the PDSCH is addressed to the terminalapparatus 1 set in the transmission mode 10, is scheduled by the DCIformat 1A to which the CRC parity bit scrambled by the C-RNTI is addedand is transmitted in the non-MBSFN subframe, the PDSCH is transmittedthrough the CRS antenna port. Here, the non-MBSFN subframe is the CRSsubframe.

For example, in a case where the PDSCH is addressed to the terminalapparatus 1 set in the transmission mode 10, is scheduled by the DCIformat 1A to which the CRC parity bit scrambled by the C-RNTI is added,and is transmitted in the MBSFN subframe, the PDSCH is transmittedthrough the URS antenna port.

For example, in a case where the PDSCH is addressed to the terminalapparatus 1 set in the transmission mode 10 and is scheduled by the DCIformat 2D to which the CRC parity bit scrambled by the C-RNTI is added,the PDSCH is transmitted through the URS antenna port.

For example, in a case where the PDSCH is addressed to the terminalapparatus 1 set in the transmission mode 10 and is scheduled by the DCIformats (the DCI format 1A and the DCI format 2D) to which the CRCparity bit scrambled by the SPS C-RNTI is added, the PDSCH istransmitted through the URS antenna port.

For example, in a case where the PDSCH is addressed to the terminalapparatus 1 set in the transmission mode 10 and is transmitted in thesubframe in which the CRS is not present, the PDSCH is transmittedthrough the URS antenna port. Here, the PDSCH is scheduled by the DCIformats (the DCI format 1A and the DCI format 2D) to which the paritybit scrambled by the SPS C-RNTI or the C-RNTI is added in the MBSFNsubframe or the non-MB SFN subframe.

Hereinafter, a method for mapping the PDSCH to the resource element willbe described.

The base station apparatus 3 transmits a higher layer signal includinginformation indicating one or a plurality of parameter sets fordetermining the resource element to which the PDSCH is mapped to theterminal apparatus 1. The terminal apparatus 1 sets the plurality ofparameter sets for determining the resource element to which the PDSCHis mapped, based on the higher layer signal received from the basestation apparatus 3. That is, the base station apparatus 3 sets theplurality of parameter sets for determining the resource element towhich the PDSCH is mapped to the terminal apparatus 1 by using thehigher layer signal. The base station apparatus 3 sets at least oneparameter set to the terminal apparatus 1 set in the transmission mode10. That is, at least one parameter is set to the terminal apparatus 1set in the transmission mode 10. One parameter set or a plurality ofparameter sets may be individually set to each of the serving cells.

The parameter set for determining the resource element to which thePDSCH is mapped includes parameter mbsfn-SubframeConfigList-r11,parameter crs-PortsCount-r11 and parameter crs-FreqShift-r11. Theparameter mbsfn-SubframeConfigList-r11 indicates the MBSFN subframe andthe non-MBSFN subframe. The parameter crs-PortsCount-r11 indicates thenumber of CRS antenna ports. The parameter crs-FreqShift-r11 indicatesthe value of the frequency shift with respect to the CRS.

The parameter mbsfn-SubframeConfigList and the parametermbsfn-SubframeConfigList-r11 may be individually set. That is, theconfiguration of the MBSFN subframe for the serving cell which isindicated by the parameter mbsfn-SubframeConfigList and theconfiguration of the MBSFN subframe which is indicated by the parametermbsfn-SubframeConfigList-r11 and is used to determine the resourceelement to which the PDSCH is mapped may be different, or may be thesame.

Here, the terminal apparatus 1 may regard the subframe that is notindicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList-r11 as the non-MBSFN subframe. For example, theparameter mbsfn-SubframeConfigList-r11 may not indicate the subframe 0and the subframe 5 as the MBSFN subframe. That is, the subframe 0 andthe subframe 5 may be constantly the non-MBSFN subframe.

The parameter crs-PortsCount-r11 may be set independently of the numberof CRS antenna ports of the serving cell. That is, the number of CRSantenna ports indicated by the parameter crs-PortsCount-r11 may bedifferent from or the same as the number of CRS antenna ports for theserving cell. The parameter crs-PortsCount-r11 indicates 0, 1, 2, or 4.

The parameter crs-FreqShift-r11 may be set independently of the value ofthe frequency shift for the CRS of the serving cell. That is, the valueof the frequency shift for the CRS indicated by the parametercrs-FreqShift-r11 may be different from or the same as the value of thefrequency shift for the CRS of the serving cell.

For example, the parameter mbsfn-SubframeConfigList-r11, the parametercrs-PortsCount-r11 and the parameter crs-FreqShift-r11 included in agiven parameter set may be related to a position of the CRS for theserving cell. For example, the parameter mbsfn-SubframeConfigList-r11,the parameter crs-PortsCount-r11 and the parameter crs-FreqShift-r11included in a given parameter set may be related to a position of theCRS for the coordinated cell.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell uses a parameter set which is scheduled by the DCI format2D to which the CRC parity bit scrambled by the C-RNTI is added andcorresponds to a value of the PQI field included in the DCI format 2D inorder to determine the resource element to which the PDSCH related tothe serving cell is mapped. An information bit indicating a valuecorresponding to one parameter set is mapped to the PQI field.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell uses a parameter set which is not accompanied by thecorresponding PDCCH/EPDCCH and corresponds to a value of the PQI fieldincluded in the DCI format 2D corresponding to SPS activation in orderto determine the resource element to which the PDSCH related to theserving cell is mapped. The PDSCH by which the correspondingPDCCH/EPDCCH is not accompanied includes PDSCHs which are periodicallyallocated using the DCI format (the DCI format 1A and the DCI format 2D)to which the CRC parity bit scrambled by the SPS C-RNTI is added.

FIG. 8 is a table showing the correspondence of the value of the PQIfield with the parameter set according to the present embodiment. InFIG. 8, 4 or less parameter sets are set to the terminal apparatus 1.For example, a value ‘00’ of the PQI field corresponds to a firstparameter set.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell uses a first parameter set in the table of FIG. 8 which isscheduled by the DCI format 1A to which the CRC parity bit scrambled bythe C-RNTI is added, is transmitted through the URS antenna port, and isused to determine the resource element to which the PDSCH related to theserving cell is mapped.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving uses a first parameter set in the table of FIG. 8 which isscheduled by the DCI format 1A to which the CRC parity bit scrambled bythe SPS C-RNTI is added and is used to determine the resource element towhich the PDSCH related to the serving cell is mapped.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell uses a first parameter set in the table of FIG. 8 which isrelated to SPS activation indicated by the DCI format 1A, is notaccompanied by the PDCCH/EPDCCH, and is used to determine the resourceelement to which the PDSCH related to the serving cell is mapped.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell uses a value of the frequency shift which is scheduled bythe DCI format 1A to which the CRC parity bit scrambled by the C-RNTI isadded, is transmitted through the CRS antenna port, and is determined bythe parameter mbsfn-SubframeConfigList, the number of CRS antenna portsfor the serving cell and the physical layer cell identity of the servingcell in order to determine the resource element to which the PDSCHrelated to the serving cell is mapped.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell may specify the position of the CRS for determining theresource element to which the PDSCH is mapped by using the value of thefrequency shift based on the parameter mbsfn-SubframeConfigList, thenumber of CRS antenna ports for the serving cell and the physical layercell identity of the serving cell in order to determine the resourceelement to which the PDSCH transmitted through the CRS antenna port inthe serving cell is mapped.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell may specify the position of the CRS for determining theresource element to which the PDSCH is mapped by using any one of theparameter sets in the table of FIG. 8 in order to determine the resourceelement to which the PDSCH transmitted through the URS antenna port inthe serving cell is mapped.

The PDSCH is not mapped to the resource element used for the URS towhich the PDSCH is related.

In a case where the parameter crs-PortsCount-r11 included in theparameter set corresponding to the PDSCH transmitted through the URSantenna port in the subframe in which the CRS is not present has a valueof 1 or greater, the terminal apparatus 1 may determine the resourceelement to which the PDSCH is mapped by assuming the number of CRSantenna ports indicated by the parameter crs-PortsCount-r11.

In the case where the parameter crs-PortsCount-r11 included in theparameter set corresponding to the PDSCH transmitted through the URSantenna port in the subframe in which the CRS is not present has a valueof 1 or greater, the terminal apparatus 1 may determine the resourceelement to which the PDSCH is mapped by assuming that the number of CRSantenna ports is 0 irrespective of the parameter crs-PortsCount-r11.

Accordingly, it is possible to associate the same parameter set withboth the PDSCH transmitted in the subframe in which the CRS is presentand the PDSCH transmitted in the subframe in which the CRS is notpresent.

The parameter noCRS-Config-r12 may be included in each of the parametersets. Here, one parameter SubframeSetConfig which is shared by theplurality of parameter sets may be set to the terminal apparatus 1, andindividual parameters noCRS-SubframeSetConfig-r12 of the parameter setsmay be set to the terminal apparatus 1.

The terminal apparatus 1 set in the transmission mode 10 for a givenserving cell may use the parameter noCRS-Config-r12 included in theparameter set corresponding to the PDSCH in order to determine theresource element to which the PDSCH transmitted through the URS antennaport in the serving cell is mapped. Accordingly, the base stationapparatus 3 can set the parameter noCRS-Config-r12 included in each ofthe parameter sets to the terminal apparatus 1 by using the higher layersignal depending on whether or not the CRS is actually transmitted ineach of the cells (transmission points).

In a case where the parameter noCRS-Config-r12 is not set, the terminalapparatus 1 may regard all the subframes as the CRS subframes.

The base station apparatus 3 determines the resource element to whichthe PDSCH is mapped based on the aforementioned method.

Hereinafter, the transmission power allocation of the downlink in afirst embodiment of the present invention will be described.

Downlink power control is expressed by energy per resource element(EPRE) for each resource element. Resource element energy means energybefore the cyclic prefix (CP) is inserted. The term “resource elementenergy” means an average energy over all constellation points for anapplied modulation method. The base station apparatus 3 determinesdownlink transmission energy for each resource element in the servingcell and the coordinated cell.

The base station apparatus 3 sets parameter referenceSignaLPowerindicating CRS EPRE of the serving cell to the terminal apparatus 1 byusing the higher layer signal. The base station apparatus 3 allow theCRS EPRE to be constant over all the subframes and to be constant over adownlink system bandwidth until different parametersreferenceSignaLPower are transmitted. The terminal apparatus 1 allowsthe CRS EPRE to be constant over all the subframes and to be constantover the downlink system bandwidth until different parametersreferenceSignaLPower are received. The base station apparatus 3 mayreduce the power of the PDSCH in the OFDM symbol including the CRS inorder to boost the power of the CRS. The base station apparatus 3 mayindividually control the CRS EPRE in the serving cell and thecoordinated cell.

A ratio between PDSCH EPRE for each OFDM symbol and CRS EPRE of theserving cell is expressed by ρ_(A) or ρ_(B). A ratio, which is expressedby ρ_(A), between the PDSCH EPRE for each OFDM symbol and the CRS EPREof the serving cell is referred to as a first ratio. A ratio, which isexpressed by ρ_(B), between the PDSCH EPRE for each OFDM symbol and theCRS EPRE of the serving cell is referred to as a second ratio. The basestation apparatus 3 sets a parameter P_(A)(p-a) used to determine theρ_(A) and a parameter P_(B)(p-b) used to determine a third ratio(ρ_(B)/ρ_(A)) of the second ratio (ρ_(B)) to the first ratio (ρ_(A)) tothe terminal apparatus 1 by using the higher layer signal.

In order to demodulate the PDSCH to which QAM modulation is applied andwhich is transmitted through the CRS antenna port, the terminalapparatus 1 specifies the first ratio (ρ_(A)), the second ratio (ρ_(B))and the third ratio (ρ_(B)/ρ_(A)). That is, in a case where the URS isnot present in PRB to which the corresponding PDSCH is mapped, in orderto demodulate the PDSCH modulated using the QAM, the terminal apparatus1 specifies the first ratio (ρ_(A)), the second ratio (ρ_(B)) and thethird ratio (ρ_(B)/ρ_(A)).

In a case where the URS is present in the physical resource block towhich the PDSCH addressed to the terminal apparatus 1 set in thetransmission mode 10 is mapped, in the base station apparatus 3, a ratioof the PDSCH EPRE to the URS EPRE within the OFDM symbol including theURS is 0 dB in a case where the number of transmission layers is equalto or less than 2, and is −3 dB in a case where the number oftransmission layers is greater than 2. The URS is transmitted in theOFDM symbol in which the ratio of the corresponding PDSCH EPRE to theCRS EPRE of the serving cell is expressed by ρ_(A). That is, in order todemodulate the PDSCH transmitted through the URS antenna port, theterminal apparatus 1 needs to specify the third ratio (ρ_(B)/ρ_(A)). Inorder to demodulate the PDSCH transmitted through the URS antenna port,the terminal apparatus 1 may not specify the first ratio (ρ_(A)) and thesecond ratio (ρ_(B)).

FIG. 9 is a table showing the third ratio (ρ_(B)/ρ_(A)) according to thepresent embodiment. The third ratio is given based on the parameterP_(B) and the number of CRS antenna ports. The third ratio may not bedefined for the subframe in which the CRS is not present. That is, in acase where the number of CRS antennal ports is 0, the third ratio maynot be defined. In a case where the PDSCH is transmitted through the CRSantenna port or the URS antenna port in the subframe in which the CRS ispresent, the terminal apparatus 1 set in the transmission mode 10regards the number of CRS antenna ports of FIG. 9 as being the number ofCRS antenna ports for the serving cell. That is, in the case where thePDSCH is transmitted through the CRS antenna port or the URS antennaport in the subframe in which the CRS is present, the terminal apparatus1 set in the transmission mode 10 specifies the third ratio(ρ_(B)/ρ_(A)) based on the number of CRS antenna ports for the servingcell.

In a case where the PDSCH is transmitted through the URS antenna port inthe subframe in which the CRS is present, the terminal apparatus 1 setin the transmission mode 10 may regard the number of CRS antenna portsof FIG. 9 as being the number of CRS antenna ports indicated by theparameter crs-PortsCount-r11 corresponding to the PDSCH. That is, in acase where the PDSCH is transmitted through the URS antenna port in thesubframe in which the CRS is present, the terminal apparatus 1 set inthe transmission mode 10 may specify the third ratio (ρ_(B)/ρ_(A)) basedon the number of CRS antenna ports indicated by the parametercrs-PortsCount-r11 corresponding to the PDSCH. Accordingly, it ispossible to efficiently set the transmission power for the transmissionof the PDSCH based on the number of CRS antenna ports that is actuallyused in the coordinated cell (the second transmission point).

FIG. 10 is a table showing an OFDM symbol index within the slot of thenon-MBSFN subframe, in which the ratio of the corresponding PDSCH EPREto the CRS EPRE of the serving cell is expressed by ρ_(A) or ρ_(B) inthe present embodiment.

FIG. 11 is a table showing an OFDM symbol index within the slot of theMBSFN subframe, in which the ratio of the corresponding PDSCH EPRE tothe CRS EPRE of the serving cell is expressed by ρ_(A) or ρ_(B) in thepresent embodiment. n_(s) indicates a slot number in the radio frame.

In a case where the PDSCH is transmitted through the URS antenna port inthe subframe in which the CRS is not present, the terminal apparatus 1set in the transmission mode 10 may regard the number of CRS antennaports of the FIGS. 10 and 11 as being 0 irrespective of the number ofthe CRS antenna ports indicated by the parameter crs-PortsCount-r11corresponding to the PDSCH and the number of CRS antenna ports for theserving cell.

In the case where the PDSCH is transmitted through the URS antenna portin the subframe in which the CRS is not present, the terminal apparatus1 set in the transmission mode 10 may determine the number of CRSantenna ports of FIGS. 10 and 11 based on the number of CRS antennaports indicated by the parameter crs-PortsCount-r11 corresponding to thePDSCH.

In a case where the PDSCH is transmitted through the CRS antenna port orthe URS antenna port in the subframe in which the CRS is present and thesubframe is indicated as the non-MBSFN subframe by the parametermbsfn-SubframeConfigList, the terminal apparatus 1 set in thetransmission mode 10 specifies the OFDM symbol index within the slot ofthe subframe, in which the ratio of the corresponding PDSCH EPRE to theCRS EPRE of the serving cell is expressed by ρ_(A) or ρ_(B) based on thetable of FIG. 10.

In a case where the PDSCH is transmitted through the CRS antenna port orthe URS antenna port in the subframe in which the CRS is present and thesubframe is indicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList, the terminal apparatus 1 set in thetransmission mode 10 specifies the OFDN symbol index within the slot ofthe subframe, in which the ratio of the corresponding PDSCH EPRE to theCRS EPRE of the serving cell is expressed by ρ_(A) or ρ_(B) based on thetable of FIG. 11.

FIG. 12 is a diagram showing an example of the OFDM symbol indexcorresponding to the ρ_(A) or ρ_(B) according to the present embodiment.FIG. 13 is a diagram showing another example of the OFDM symbol indexcorresponding to the ρ_(A) or ρ_(B) according to the present embodiment.FIGS. 12 and 13 show one subframe in the time domain and two physicalresource blocks expressed by the bandwidth of one downlink physicalresource block in the frequency domain.

In FIGS. 12 and 13, the following conditions 1 to 9 are satisfied.

-   -   Condition 1: CRS is present    -   Condition 2: Number of CRS antenna ports for serving cell is 4    -   Condition 3: Value of frequency shift of CRS for serving cell is        0    -   Condition 4: Subframe is indicated as MBSFN subframe by        parameter mbsfn-SubframeConfigList for serving cell    -   Condition 5: PDSCHs are transmitted through URS antenna ports 7        to 14    -   Condition 6: Number of CRS antenna ports indicated by parameter        crs-PortsCount-r11 included in parameter set corresponding PDSCH        is 1    -   Condition 7: Value of frequency shift indicated by parameter        crs-FreqShift-r11 included in parameter set corresponding to        PDSCH is 0    -   Condition 8: Subframe is indicated as non-MB SFN subframe by        parameter mbsfn-SubframeConfigList-r11 included in parameter set        corresponding to PDSCH    -   Condition 9: Resource element to which PDSCH is mapped is        determined based on at least parameter crs-PortsCount-r11,        parameter crs-FreqShift-r11 and parameter        mbsfn-SubframeConfigList-r11.

In FIGS. 12 and 13, squares to which Ri (i=0, 1, 2, and 3) is assignedindicate resource elements to which the CRS transmitted through a CRSantenna port i is mapped. In FIGS. 12 and 13, squares to which U7 isassigned indicate resource elements to which the URS transmitted throughURS antenna ports {7, 8, 11, 13} is mapped, and squares to which U9 isassigned indicate resource elements to which the URS transmitted throughURS antenna ports {9, 10, 12, 14} is mapped. In FIGS. 12 and 13, squareshatched by dots indicate resource elements to which the PDSCH is mapped.

In FIG. 12, the terminal apparatus 1 set in the transmission mode 10specifies the OFDM symbol index within the slot of the MBSFN subframe,in which the ratio of the corresponding PDSCH EPRE to the CRS EPRE ofthe serving cell is expressed by the ρ_(A) or ρ_(B), based on a rowcorresponding a case where the number of CRS antenna ports is 4 in thetable of FIG. 11. That is, in FIG. 12, the OFDM symbols having theindices 0 and 1 within the slots satisfying n_(s) mod 2=0 correspond tothe ρ_(B), and other OFDM symbols correspond to the ρ_(A).

As stated above, the terminal apparatus 1 and the base station apparatus3 can specify the OFDM symbol index within the slot of the subframe, inwhich the ratio of the corresponding PDSCH EPRE to the CRS EPRE of theserving cell is expressed by the ρ_(A) or ρ_(B), based on the number ofCRS antenna ports for the serving cell and the parametermbsfn-SubframeConfigList for the serving cell, irrespective of theparameter set. Since the OFDM symbol index within the slot of thesubframe can be specified, the structures of the terminal apparatus 1and the base station apparatus 3 can be simplified.

In FIG. 12, the OFDM symbol index within the slot of the subframe, inwhich the ratio of the corresponding PDSCH EPRE to the CRS EPRE of theserving cell is expressed by the ρ_(A) or ρ_(B), is specified based on aposition of the CRS different from the position of the CRS used todetermine the resource element to which the PDSCH is mapped. As aresult, even though the CRS is not included in the OFDM symbol havingthe index 1 in the slot satisfying n_(s) mod 2=0 in FIG. 12, the PDSCHEPRE for boosting the CRS may be reduced, and even though the CRS isincluded in the OFDM symbols having the index 4 in the slot satisfyingn_(s) mode 2=0 and the OFDM symbols having the indices 0 and 4 in theslot satisfying n_(s) mode 2=1 in FIG. 12, the PDSCH EPRE for boostingthe CRS is not reduced. Accordingly, there is a problem that thetransmission power for the transmission of the PDSCH and the boosting ofthe CRS is not appropriately performed.

In a case where the PDSCH is transmitted through the URS antenna port inthe subframe in which the CRS is present and the subframe is indicatedas the non-MB SFN subframe by the parameter mbsfn-SubframeConfigList-r11included in the parameter set corresponding to the PDSCH, the terminalapparatus 1 set in the transmission mode 10 may specify the OFDM symbolindex within the slot of the subframe, in which the ratio of thecorresponding PDSCH EPRE to the CRS EPRE of the serving cell isexpressed by the ρ_(A) or ρ_(B), based on the table of FIG. 10.

In a case where the PDSCH is transmitted through the URS antenna port inthe subframe in which the CRS is present and the subframe is indicatedas the MBSFN subframe by the parameter mbsfn-SubframeConfigList-r11included in the parameter set corresponding to the PDSCH, the terminalapparatus 1 set in the transmission mode 10 may specify the OFDM symbolindex within the slot of the subframe, in which the ratio of thecorresponding PDSCH EPRE to the CRS EPRE of the serving cell isexpressed by the ρ_(A) or ρ_(B), based on the table of FIG. 11.

In a case where the PDSCH is transmitted through the URS antenna port inthe subframe in which the CRS is present, the terminal apparatus 1 setin the transmission mode 10 may specify the OFDM symbol index within theslot of the subframe, in which the ratio of the corresponding PDSCH EPREto the CRS EPRE of the serving cell is expressed by the ρ_(A) or ρ_(B),based on the table of FIG. 10 or 11 and the parameter crs-FreqShift-r11included in the parameter set corresponding to the PDSCH.

In FIG. 13, the terminal apparatus 1 set in the transmission mode 10specifies the OFDM symbol index within the slot of the non-MB SFN, inwhich the ratio of the corresponding PDSCH EPRE to the CRS EPRE of theserving cell is expressed by the ρ_(A) or ρ_(B), based on a rowcorresponding to a case where the number of CRS antenna ports in thetable of FIG. 10 is 1. That is, in FIG. 13, the OFDM symbols having theindices 0 and 4 in the slots satisfying n_(s) mode 2=0, 1 correspond tothe ρ_(B), and other OFDM symbols correspond to the ρ_(A).

As discussed above, since the terminal apparatus 1 and the base stationapparatus 3 can specify the OFDM symbol index within the slot of thesubframe, in which the ratio of the corresponding PDSCH EPRE to the CRSEPRE of the serving cell is expressed by the ρ_(A) or ρ_(B), based onthe parameter set corresponding to the PDSCH, irrespective of the numberof CRS antenna ports for the serving cell and the parametermbsfn-SubframeConfigList for the serving cell, the base stationapparatus 3 appropriately can control the transmission power for thetransmission of the PDSCH and the boosting of the CRS.

Hereinafter, the structures of the apparatuses according to the presentembodiment will be described.

FIG. 14 is a schematic block diagram showing the structure of theterminal apparatus 1 according to the present embodiment. As shown inthe drawing, the terminal apparatus 1 includes a higher layer processingunit 101, a control unit 103, a reception unit 105, a transmission unit107, and a transmission/reception antenna 109. The higher layerprocessing unit 101 includes a radio resource control unit 1011, ascheduling information interpretation unit 1013, and a reception controlunit 1015. The reception unit 105 includes a decoding unit 1051, ademodulation unit 1053, a demultiplexing unit 1055, a wireless receptionunit 1057, and a channel measuring unit 1059. The transmission unit 107includes a coding unit 1071, a modulation unit 1073, a multiplexing unit1075, a wireless transmission unit 1077, and an uplink reference signalgenerating unit 1079.

The higher layer processing unit 101 outputs uplink data (transportblock) generated by, for example, the operation of a user to thetransmission unit 107. The higher layer processing unit 101 processes amedium access control (MAC) layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a radio resourcecontrol (RRC) layer.

The radio resource control unit 1011 of the higher layer processing unit101 manages various kinds of configuration information of the terminalapparatus. The radio resource control unit 1011 sets various types ofconfiguration information/parameters based on the higher layer signalreceived from the base station apparatus 3. That is, the radio resourcecontrol unit 1011 sets various types of configurationinformation/parameters based on information indicating various types ofconfiguration information/parameters received from the base stationapparatus 3. In addition, the radio resource control unit 1011 generatesinformation arranged in each uplink channel, and outputs the informationto the transmission unit 107.

The scheduling information interpretation unit 1013 of the higher layerprocessing unit 101 interprets the DCI format (scheduling information)which is received through the reception unit 105, generates controlinformation for controlling the reception unit 105 and the transmissionunit 107, based on the interpretation result of the DCI format, andoutputs the control information to the control unit 103.

The reception control unit 1015 of the higher layer processing unit 101specifies the resource element to which the PDSCH is mapped, the firstratio ρ_(A), the second ratio ρ_(B), the third ratio (ρ_(A)/ρ_(B)), theOFDM symbol index corresponding to the first ratio ρ_(A) and/or the OFDMsymbol index corresponding to the second ratio ρ_(B), based on thevarious types of configuration information/parameters managed by theradio resource control unit 1011. The reception unit 105 or thedemultiplexing unit 1055 may have the function of the reception powercontrol unit 1015.

The control unit 103 generates control signals for controlling thereception unit 105 and the transmission unit 107, based on the controlinformation from the higher layer processing unit 101. The control unit103 outputs the generated control signals to the reception unit 105 andthe transmission unit 107 to control the reception unit 105 and thetransmission unit 107.

The reception unit 105 performs demultiplexing, demodulation, anddecoding on the reception signal which is received from the base stationapparatus 3 through the transmission/reception antenna 109 in responseto the control signal input from the control unit 103, and outputs thedecoded information to the higher layer processing unit 101.

The wireless reception unit 1057 converts (down-conversion) the downlinksignal received through the transmission/reception antenna 109 into abaseband signal through orthogonal demodulation to remove an unnecessaryfrequency component, controls an amplification level such that a signallevel is appropriately maintained, performs the orthogonal demodulationon the signal, based on the orthogonal component and an in-phasecomponent of the received signal, and converts theorthogonal-demodulated analog signal into a digital signal. The wirelessreception unit 1057 removes a portion corresponding to a cyclic prefix(CP) from the converted digital signal, performs a fast Fouriertransform (FFT) on a signal from which the CP has been removed, andextracts a signal of the frequency domain.

The demultiplexing unit 1055 demultiplexes the extracted signal into thePHICH, the PDCCH, the EPDCCH, the PDSCH, and the downlink referencesignal. In addition, the demultiplexing unit 1055 compensates for thechannel of the PHICH, the PDCCH, the EPDCCH, and the PDSCH from theestimated value of the channel input from the channel measuring unit1059. The demultiplexing unit 1055 outputs the demultiplexed downlinkreference signal to the channel measuring unit 1059.

The demodulation unit 1053 multiplies the PHICH by a corresponding codeto synthesize them, demodulates the synthesized signal using a binaryphase shift keying (BPSK) modulation method, and outputs the demodulatedsignal to the decoding unit 1051. The decoding unit 1051 decodes thePHICH addressed to the terminal apparatus, and outputs the decoded HARQindicator to the higher layer processing unit 101. The demodulation unit1053 demodulates the PDCCH and/or the EPDCCH using a QPSK modulationmethod, and outputs the demodulated PDCCH and/or EPDCCH to the decodingunit 1051. The decoding unit 1051 tries to decode the PDCCH and/or theEPDCCH. In a case where decoding has succeeded, the decoding unitoutputs the decoded downlink control information and the RNTIcorresponding to the downlink control information to the higher layerprocessing unit 101.

The demodulation unit 1053 demodulates the PDSCH using a modulationmethod notified by the downlink grant, such as quadrature phase shiftkeying (QPSK), 16-quadrature amplitude modulation (QAM), or 64 QAM, andoutputs the demodulated PDSCH to the decoding unit 1051. The decodingunit 1051 performs decoding, based on information related to a codingrate notified by downlink control information, and outputs the decodeddownlink data (transport block) to the higher layer processing unit 101.

The channel measuring unit 1059 measures a downlink path loss or adownlink channel state from the downlink reference signal input from thedemultiplexing unit 1055, and outputs the measured path loss or channelstate to the higher layer processing unit 101. The channel measuringunit 1059 calculates an estimated value of the channel of the downlinkfrom the downlink reference signal, and outputs the estimated value tothe demultiplexing unit 1055. The channel measuring unit 1059 performschannel measurement and/or interference measurement in order tocalculate the CQI.

The transmission unit 107 generates an uplink reference signal inresponse to the control signal input from the control unit 103, codesand modulates the uplink data (transport block) input from the higherlayer processing unit 101, multiplexes the PUCCH, the PUSCH, and thegenerated uplink reference signal, and transmits the multiplexed signalto the base station apparatus 3 through the transmission/receptionantenna 109.

The coding unit 1071 performs coding, such as convolution cording orblock coding, on the uplink control information input from the higherlayer processing unit 101.

In addition, the coding unit 1071 performs turbo cording, based on theinformation used to schedule the PUSCH.

The modulation unit 1073 modulates coded bits input from the coding unit1071 using a modulation method notified by downlink control informationsuch as BPSK, QPSK, 16 QAM and 64 QAM or a modulation method previouslydetermined for each channel. The modulation unit 1073 determines thenumber of data sequences on which spatial multiplexing is performedbased on information used for scheduling of the PUSCH, maps a pluralityof uplink data items transmitted on the same PUSCH to a plurality ofsequences by using multiple-input multiple-output (MIMO) spatialmultiplexing (SM), and performs precoding on the sequences.

The uplink reference signal generating unit 1079 generates sequencesobtained by a predetermined rule (expression), based on a physical cellidentity (PCI, referred to as a cell ID) for identifying the basestation apparatus 3, a bandwidth in which the uplink reference signal isarranged, a cyclic shift notified by the uplink grant, and a parametervalue for generating the DMRS sequence. The multiplexing unit 1075rearranges modulated symbols of the PUSCH in parallel in response to thecontrol signals input from the control unit 103, and performs a discreteFourier transform (DFT) on the rearranged symbols. The multiplexing unit1075 multiplexes the PUCCH and PUSCH signals and the generated uplinkreference signal for each transmission antenna port. That is, themultiplexing unit 1075 arranges the PUCCH and PUSCH signals and thegenerated uplink reference signal in the resource elements for eachtransmission antenna port.

The wireless transmission unit 1077 performs an inverse fast Fouriertransform (IFFT) on the multiplexed signals to generate the SC-FDMAsymbols, adds the CP to the generated SC-FDMA symbol to generate abaseband digital signal, and converts the baseband digital signal intoan analog signal. Thereafter, the wireless transmission unit removesextra frequency components using a low-pass filter, and performsup-conversion on a signal having a carrier frequency. Subsequently, thewireless transmission unit amplifies a power, and transmits theamplified signal to the transmission/reception antenna 109.

FIG. 15 is a schematic block diagram showing the structure of the basestation apparatus 3 according to the present embodiment. As shown in thedrawing, the base station apparatus 3 includes a higher layer processingunit 301, a control unit 303, a reception unit 305, a transmission unit307, and a transmission/reception antenna 309. The higher layerprocessing unit 301 includes a radio resource control unit 3011, ascheduling unit 3013, and a transmission control unit 3015. Thereception unit 305 includes a decoding unit 3051, a demodulation unit3053, a demultiplexing unit 3055, a wireless reception unit 3057, and achannel measuring unit 3059. The transmission unit 307 includes a codingunit 3071, a modulation unit 3073, a multiplexing unit 3075, a wirelesstransmission unit 3077, and a downlink reference signal generating unit3079.

The higher layer processing unit 301 processes a medium access control(MAC) layer, a packet data convergence protocol (PDCP) layer, a radiolink control (RLC) layer, and a radio resource control (RRC) layer. Inaddition, the higher layer processing unit 301 generates controlinformation for controlling the reception unit 305 and the transmissionunit 307, and outputs the control information to the control unit 303.

The radio resource control unit 3011 of the higher layer processing unit301 generates, for example, downlink data (transport block), systeminformation, an RRC message, and a MAC control element (CE) to bearranged in downlink PDSCH or acquires these information items from ahigher node, and outputs these information items to the transmissionunit 307. In addition, the radio resource control unit 3011 managesvarious kinds of configuration information/parameters of each of theterminal apparatuses 1.

The radio resource control unit 1011 may set the various types ofconfiguration information/parameters to each the terminal apparatuses 1by using the higher layer signal. That is, the radio resource controlunit 1011 transmits and broadcasts information indicating various typesof configuration information/parameters.

The scheduling unit 3013 of the higher layer processing unit 301determines a frequency and a subframe to which the physical channels(PDSCH and PUSCH) are allocated, a coding rate and a modulation methodof the physical channels (PDSCH and PUSCH), and a transmission powerfrom the received channel state information, the channel quality and theestimated value of the channel input from the channel measuring unit3059. The scheduling unit 3013 generates control information (forexample, the DCI format) for controlling the reception unit 305 and thetransmission unit 307, based on the scheduling result, and outputs thegenerated control information to the control unit 303. The schedulingunit 3013 further determines a timing when the transmitting process andthe receiving process are performed.

The transmission control unit 3015 of the higher layer processing unit301 determines the resource element to which the PDSCH is mapped, thefirst ratio ρ_(A), the second ratio ρ_(B), the third ratio(ρ_(A)/ρ_(B)), the OFDM symbol index corresponding to the first ratioρ_(A) and/or the OFDM symbol index corresponding to the second ratioρ_(B), based on the various types of configurationinformation/parameters managed by the radio resource control unit 1011,and controls the mapping of the PDSCH and the PDSCH EPRE. Thetransmission unit 307 and the multiplexing unit 305 may have a functionof the transmission power control unit 3015.

The control unit 303 generates control signals for controlling thereception unit 305 and the transmission unit 307, based on the controlinformation from the higher layer processing unit 301. The control unit303 outputs the generated control signals to the reception unit 305 andthe transmission unit 307 to control the reception unit 305 and thetransmission unit 307.

The reception unit 305 performs demultiplexing, demodulation anddecoding on the reception signal received from the terminal apparatus 1through the transmission/reception antenna 309 in response to thecontrol signals input from the control unit 303, and outputs the decodedinformation to the higher layer processing unit 301. The wirelessreception unit 3057 converts the uplink signal received through thetransmission/reception antenna 309 into a baseband signal throughorthogonal demodulation (down-conversion), and removes unnecessaryfrequency components. Thereafter, the wireless reception unit controlsan amplification level such that the signal level is appropriatelymaintained, performs orthogonal demodulation on the signal based on thein-phase component and the orthogonal component of the received signal,and converts the orthogonal-demodulated analog signal into a digitalsignal.

The wireless reception unit 3057 removes a portion corresponding to acyclic prefix (CP) from the converted digital signal. The wirelessreception unit 3057 performs fast Fourier transform (FFT) on the signalfrom which the CP has been removed, extracts a signal of the frequencydomain, and outputs the extracted signal to the demultiplexing unit3055.

The demultiplexing unit 1055 demultiplexes the signal input from thewireless reception unit 3057 into signals, such as the PUCCH, the PUSCH,and the uplink reference signal. The demultiplexing process ispreviously determined by the radio resource control unit 3011 of thebase station apparatus 3, and is performed based on the allocationinformation of the radio resources included in the uplink grant which isnotified to each terminal apparatus 1. In addition, the demultiplexingunit 3055 compensates for the channels of the PUCCH and the PUSCH fromthe estimated value of the channel input from the channel measuring unit3059. The demultiplexing unit 3055 outputs the demultiplexed uplinkreference signal to the channel measuring unit 3059.

The demodulation unit 3053 performs inverse discrete Fourier transform(IDFT) on the PUSCH to acquire modulated symbols, and demodulates thereceived signal using a modulation method which is predetermined foreach of the modulated symbols of the PUCCH and the PUSCH, apredetermined modulation method such as BPSK, QPSK, 16 QAM, or 64 QAM,or a modulation method which is previously notified from the basestation apparatus to each terminal apparatus 1 using the uplink grant.The demodulation unit 3053 demultiplexes the modulated symbols of aplurality of uplink data items which are transmitted on the same PUSCHby using the MIMO SM, based on the number of spatial-multiplexedsequences previously notified to each terminal apparatus 1 using theuplink grant and information indicating precoding on the sequences.

The decoding unit 3051 decodes the coded bits of the demodulated PUCCHand PUSCH at a predetermined coding rate of a predetermined codingmethod or a coding rate which is previously notified from the basestation apparatus to the terminal apparatus 1 using the uplink grant,and outputs the decoded uplink data and the uplink control informationto the higher layer processing unit 101. In a case where the PUSCH isretransmitted, the decoding unit 3051 performs decoding using the codedbits, which have been input from the higher layer processing unit 301and then stored in an HARQ buffer, and the demodulated coded bits. Thechannel measuring unit 309 measures, for example, the estimated value ofthe channel and the quality of the channel from the uplink referencesignal input from the demultiplexing unit 3055, and outputs the measuredvalues to the demultiplexing unit 3055 and the higher layer processingunit 301.

The transmission unit 307 generates a downlink reference signal,performs coding and modulation on the HARQ indicator, downlink controlinformation, and downlink data input from the higher layer processingunit 301, multiplexes the PHICH, the PDCCH, the EPDCCH, the PDSCH, andthe downlink reference signal, and transmits the signals to the terminalapparatus 1 through the transmission/reception antenna 309, in responseto the control signal input from the control unit 303.

The coding unit 3071 codes the HARQ indicator, downlink controlinformation, and downlink data input from the higher layer processingunit 301 using a predetermined coding method, such as block coding,convolution coding, or turbo coding, or the coding method determined bythe radio resource control unit 3011. The modulation unit 3073 modulatesthe coded bits input from the coding unit 3071 using a predeterminedmodulation method such as BPSK, QPSK, 16 QAM or 64 QAM, or themodulation method determined by the radio resource control unit 3011.

The downlink reference signal generating unit 3079 generates, as thedownlink reference signal, the sequence which has been known to theterminal apparatus 1 and is calculated according to a predeterminedrule, based on the physical cell identity (PCI) for identifying the basestation apparatus 3. The multiplexing unit 3075 multiplexes themodulated symbol of each modulated channel and the generated downlinkreference signal. That is, the multiplexing unit 3075 arranges themodulated symbol of each modulated channel and the generated downlinkreference signal in the resource elements.

The wireless transmission unit 3077 performs inverse fast Fouriertransform (IFFT) on the multiplexed modulated symbol to generate theOFDM symbol, adds the CP to the generated OFDM symbol, and generates abaseband digital signal. Subsequently, the wireless transmission unitconverts the baseband digital signal into an analog signal, removesextra frequency components by a low pass filter, and performsup-conversion on the signal having a carrier frequency. Thereafter, thewireless transmission unit amplifies a power, and outputs and transmitsthe amplified power through the transmission/reception antenna 309.

That is, the terminal apparatus 1 according to the present embodimentincludes the reception unit 105 that receives information indicating theparameter noCRS-Config-r12 indicating the subframe in which the CRS isnot present, information indicating the parametermbsfn-SubframeConfigList indicating the MBSFN subframe in the servingcell, information indicating the parameter mbsfn-SubframeConfigList-r11indicating the MBSFN subframe and determining the resource element towhich the PDSCH is mapped, information indicating the parametercrs-PortsCount-r11 indicating the number of CRS antenna ports anddetermining the resource element to which the PDSCH is mapped, andinformation indicating the parameter p-b related to the third ratiobetween the first ratio of the PDSCH EPRE to the CRS EPRE of the servingcell and the second ratio of the PDSCH EPRE to the CRS EPRE of theserving cell.

In a case where the PDSCH transmitted through the URS antenna portdifferent from the CRS antenna port for the serving cell is received inthe subframe indicated as the subframe in which the CRS is not presentby the parameter noCRS-Config-r12, the reception unit 105 and/or thereception control unit 1015 of the terminal apparatus 1 according to thepresent embodiment specifies the OFDM symbol corresponding to the firstratio and the resource element to which the PDSCH is mapped by assumingthat the number of CRS antenna ports is 0, irrespective of the number ofthe CRS antenna ports indicated by the parameter crs-PortsCount-r11corresponding to the PDSCH.

In the case where the PDSCH transmitted through the URS antenna portdifferent from the CRS antenna port for the serving cell is received,the reception unit 105 and/or the reception control unit 1015 mayspecify the resource element to which the PDSCH is mapped, the OFDMsymbol corresponding to the second ratio and the OFDM symbolcorresponding to the first ratio, based on the number of CRS antennaports indicated by the parameter crs-PortsCount-r11 corresponding to thePDSCH and whether or not the subframe in which the PDSCH is received isindicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList-r11, even though the subframe in which thePDSCH is received is indicated as the subframe in which the CRS is notpresent by the parameter noCRS-Config-r12.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set and the PDSCH, which is mapped tothe resource element determined based on at least the parametermbsfn-SubframeConfigst-r11 and the parameter crs-PortsCount-r11 in asubframe other than the subframe indicated as the subframe in which theCRS is not present by the parameter noCRS-Config-r12 and is transmittedthrough the URS antenna port different from the CRS antenna port for theserving cell, is received, the reception unit 105 and/or the receptioncontrol unit 1015 specifies the OFDM symbol corresponding to the firstratio and the OFDM symbol corresponding to the second ratio, based onthe number of CRS antenna ports for the serving cell and whether or notthe subframe in which the PDSCH is received is indicated as the MBSFNsubframe by the parameter mbsfn-SubframeConfigList.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set and the PDSCH, which is mapped tothe resource element determined based on at least the parametermbsfn-SubframeConfigst-r11 and the parameter crs-PortsCount-r11 in asubframe other than the subframe indicated as the subframe in which theCRS is not present by the parameter noCRS-Config-r12 and is transmittedthrough the URS antenna port different from the CRS antenna port for theserving cell, is received, the reception unit 105 and/or the receptioncontrol unit 1015 may specify the OFDM symbol corresponding to the firstratio and the OFDM symbol corresponding to the second ratio, based onthe number of CRS antenna ports indicated by the parametercrs-PortsCount-r11 and whether or not the subframe in which the PDSCH isreceived is indicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList-r11.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set and the PDSCH, which is mapped tothe resource element determined based on at least the parametermbsfn-SubframeConfigst and the number of CRS antenna ports in theserving cell in a subframe other than the subframe indicated as thesubframe in which the CRS is not present by the parameternoCRS-Config-r12 and is transmitted through the CRS antenna port for theserving cell, is received, the reception unit 105 and/or the receptioncontrol unit 1015 specifies the OFDM symbol corresponding to the firstratio and the OFDM symbol corresponding to the second ratio, based onthe number of CRS antenna ports in the serving cell and whether or notthe subframe in which the PDSCH is received is indicated as the MBSFNsubframe by the parameter mbsfn-SubframeConfigList.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are not set, the reception unit 105 and/orthe reception control unit 1015 specifies the OFDM symbol correspondingto the first ratio and the OFDM symbol corresponding to the secondratio, based on the number of CRS antenna ports in the serving cell andwhether or not the subframe in which the PDSCH is received is indicatedas the MBSFN subframe by the parameter mbsfn-SubframeConfigList.

The base station apparatus 3 according to the present embodimentincludes the transmission unit 307 that transmits information indicatingthe parameter noCRS-Config-r12 indicating the subframe in which the CRSis not present, information indicating the parametermbsfn-SubframeConfigList indicating the MBSFN subframe in the servingcell, information indicating the parameter mbsfn-SubframeConfigList-r11indicating the MBSFN subframe and determining the resource element towhich the PDSCH is mapped, information indicating the parametercrs-PortsCount-r11 indicating the number of CRS antenna ports anddetermining the resource element to which the PDSCH is mapped, andinformation indicating the parameter p-b related to the third ratiobetween the first ratio of the PDSCH EPRE to the CRS EPRE of the servingcell and the second ratio of the PDSCH EPRE to the CRS EPRE of theserving cell.

In a case where the PDSCH is transmitted through the URS antenna portdifferent from the CRS antenna port for the serving cell in the subframeindicated as the subframe in which the CRS is not present by theparameter noCRS-Config-r12, the transmission unit 307 and/or thetransmission control unit 3015 of the base station apparatus 3 accordingto the present embodiment determines the OFDM symbol corresponding tothe first ratio and the resource element to which the PDSCH is mapped,maps the PDSCH to the determined resource element, and controls thetransmission control for the PDSCH, by assuming that the number of CRSantenna ports is 0 irrespective of the number of CRS antenna portsindicated by the parameter crs-PortsCount-r11 corresponding to thePDSCH.

In a case where the PDSCH is transmitted through the URS antenna portdifferent from the CRS antenna port for the serving cell, thetransmission unit 307 and/or the transmission control unit 3015 maydetermine the resource element to which the PDSCH is mapped, the OFDMsymbol corresponding to the first ratio and the OFDM symbolcorresponding to the second ratio, may map the PDSCH to the determinedresource element, and may control the transmission power for the PDSCH,based on the number of CRS antenna ports indicated by the parametercrs-PortsCount-r11 corresponding to the PDSCH and whether or not thesubframe in which the PDSCH is transmitted is indicated as the MBSFNsubframe by the parameter mbsfn-SubframeConfigList-r11 even though thesubframe in which the PDSCH is transmitted is indicated as the subframein which the CRS is not present by the parameter noCRS-Config-r12.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set to the terminal apparatus, thePDSCH is mapped to the resource element determined based on at least theparameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 in a subframe other than the subframeindicated as the subframe in which the CRS is not present by theparameter noCRS-Config-r12 and the PDSCH is transmitted through the URSantenna port different from the CRS antenna port for the serving cell,the transmission unit 307 and/or the transmission control unit 3015determines the OFDM symbol corresponding to the first ratio and the OFDMsymbol corresponding to the second ratio, and controls the transmissionpower for the PDSCH, based on the number of CRS antenna ports for theserving cell and whether or not the subframe in which the PDSCH istransmitted is indicated as the MBSFN subframe by the parametermbsfn-SubframeConfigList.

In the case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set to the terminal apparatus, thePDSCH is mapped to the resource element determined based on at least theparameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 in a subframe other than the subframeindicated as the subframe in which the CRS is not present by theparameter noCRS-Config-r12, and the PDSCH is transmitted through the URSantenna port different from the CRS antenna port for the serving cell,the transmission unit 307 and/or the transmission control unit 3015 maydetermine the OFDM symbol corresponding to the first ratio and the OFDMsymbol corresponding to the second ratio, and may control thetransmission power for the PDSCH, based on the number of CRS antennaports indicated by the parameter crs-PortsCount-r11 and whether or notthe subframe in which the PDSCH is transmitted is indicated as the MBSFNsubframe by the parameter mbsfn-SubframeConfigList-r11.

In the case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are set to the terminal apparatus, thePDSCH is mapped to the resource element determined based on at least theparameter mbsfn-SubframeConfigList and the number of CRS antenna portsin the serving cell in a subframe other than the subframe indicated asthe subframe in which the CRS is not present by the parameternoCRS-Config-r12, and the PDSCH is transmitted through the same antennaport as the CRS antenna port for the serving cell, the transmission unit307 and/or the transmission control unit 3015 specifies the OFDM symbolcorresponding to the first ratio and the OFDM symbol corresponding tothe second ratio, and controls the transmission power for the PDSCH,based on the number of CRS antenna ports in the serving cell and whetheror not the subframe in which the PDSCH is transmitted is indicated asthe MBSFN subframe by the parameter mbsfn-SubframeConfigList.

In a case where the parameter crs-PortsCount-r11 and the parametermbsfn-SubframeConfigList-r11 are not set to the terminal apparatus andthe PDSCH is received in a subframe other than the subframe indicated asthe subframe in which the CRS is not present by the parameternoCRS-Config-r12, the transmission unit 307 and/or the transmissioncontrol unit 3015 specifies the OFDM symbol corresponding to the firstratio and the OFDM symbol corresponding to the second ratio, andcontrols the transmission power for the PDSCH, based on the number ofCRS antenna ports in the serving cell and whether or not the subframe inwhich the PDSCH is received is indicated as the MBSFN subframe by theparameter mbsfn-SubframeConfigList.

The specifying of the OFDM symbol means that the index of the OFDM isspecified.

Accordingly, the terminal apparatus and the base station apparatus canefficiently communicate using the PDSCH. It is possible to efficientlymap the downlink physical channel to the resource element. It ispossible to efficiently control the transmission power for thetransmission on the downlink physical channel.

The program which runs on the base station apparatus 3 and the terminalapparatus 1 according to the present invention may be a program (whichcauses a computer to function) which controls a central processing unit(CPU) such that the functions of the above-described embodiment of thepresent invention are implemented. The information handled by theseapparatuses is temporarily stored in a random access memory (RAM) duringthe process and is then stored in various types of read only memories(ROMs), such as a flash ROM, or a hard disk drive (HDD). Then, the CPUreads, corrects, and writes the information, if necessary.

Some functions of the terminal apparatus 1 and the base stationapparatus 3 according to the above-described embodiment may beimplemented by a computer. In this case, a program for implementing thecontrol function may be recorded on a computer-readable recording mediumand a computer system may read the program recorded on the recordingmedium and execute the program to implement the functions.

The term “computer system” means a computer system that is provided inthe terminal apparatus 1 or the base station apparatus 3 and includes anOS or hardware such as peripheral apparatuses. The term“computer-readable recording medium” means a portable medium, such as aflexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storingdevice, such as a hard disc provided in the computer system.

The “computer-readable recording medium” may include a recording mediumthat dynamically stores the program in a short time, such as acommunication cable used in a case where the program is transmittedthrough a network, such as the Internet, or a communication line, suchas a telephone line, and a recording medium that stores the program fora predetermined period of time, such as a volatile memory in a computersystem that serves as a server or a client in this case. The “program”may be a program that implements some of the above-mentioned functionsor a program that implements the above-mentioned functions incombination with the program which has been stored in the computersystem.

The base station apparatus 3 according to the above-described embodimentmay be realized as an aggregate (apparatus group) of a plurality ofapparatuses. Each of the apparatuses forming the apparatus group mayhave some or all of the functions or the functional blocks of the basestation apparatus 3 according to the above-described embodiment. Theapparatus group may have each function or each functional block of thebase station apparatus 3. The terminal apparatus 1 according to theabove-described embodiment can communicate with the base stationapparatus which is an aggregate of apparatuses.

The base station apparatus 3 according to the above-described embodimentmay be an evolved universal terrestrial radio access network (EUTRAN).In addition, the base station apparatus 3 according to theabove-described embodiment may have some or all of the functions of ahigher node of eNodeB.

Each of the terminal apparatus 1 and the base station apparatus 3according to the above-described embodiments may be partly or entirelyrealized in the form of an LSI, which is a typical integrated circuit,or a chip set. Each functional block of the terminal apparatus 1 and thebase station apparatus 3 may be individually integrated into a chip, orsome or all of the functional blocks may be integrated into a chip. Amethod for achieving the integrated circuit is not limited to the LSIand it may be achieved by a dedicated circuit or a general-purposeprocessor. In addition, in a case where a technique for achieving anintegrated circuit which replaces the LSI technique will be developedwith the progress of a semiconductor technique, the integrated circuitmanufactured by the developed technique can also be used.

In the above-described embodiment, the terminal apparatus is given as anexample of a terminal apparatus or a communication apparatus. However,the invention is not limited thereto. The invention can also be appliedto terminal apparatuses or communication apparatuses of stationary ornon-movable electronic apparatuses which are installed indoors oroutdoors, such as AV apparatuses, kitchen apparatuses, cleaning andwashing machines, air conditioners, office apparatuses, vendingmachines, and other home appliances.

The embodiment of the invention has been described above in detail withreference to the drawings. However, the detailed structure is notlimited to the above-described embodiment and the invention alsoincludes a change in the design within the scope and spirit of theinvention. Various modifications and changes of the invention can bemade without departing from the scope of the claims and the technicalrange of the invention includes embodiments obtained by appropriatelycombining technical means described in different embodiments. Inaddition, the elements which are described in each of theabove-described embodiments and have the same effect may be replacedwith each other.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 (1A, 1B, 1C) Terminal apparatus    -   3 Base station apparatus    -   101 Higher layer processing unit    -   103 Control unit    -   105 Reception unit    -   107 Transmission unit    -   109 Transmission and reception antenna    -   301 Higher layer processing unit    -   303 Control unit    -   305 Reception unit    -   307 Transmission unit    -   309 Transmission and reception antenna    -   1011 Radio resource control unit    -   1013 Scheduling information interpretation unit    -   1015 Reception control unit    -   3011 Radio resource control unit    -   3013 Scheduling unit    -   3015 Transmission control unit

The invention claimed is:
 1. A terminal apparatus that is configured tocommunicate with a base station apparatus, the terminal apparatuscomprising: a reception circuit configured to and/or programmed toreceive first information indicating a first subframe in which acell-specific reference signal (CRS) is present, and second informationwhich indicates the number of CRS antenna ports and is used to determinea resource element to which a physical downlink control channel (PDSCH)is mapped, wherein, in a second subframe other than the first subframe,a PDSCH transmitted through an antenna port different from a CRS antennaport for a serving cell is mapped to a resource element, the resourceelement being determined based on the number of CRS antenna portsindicated by the second information corresponding to the PDSCH.
 2. Theterminal apparatus according to claim 1, wherein the reception circuitis configured to and/or programmed to receive third informationindicating a third ratio between a first ratio of PDSCH energy perresource element (EPRE) to CRS EPRE of a serving cell and a second ratioof PDSCH EPRE to CRS EPRE of a serving cell, and in the second subframe,an orthogonal frequency division multiplexing (OFDM) symbolcorresponding to the first ratio and an OFDM symbol corresponding to thesecond ratio are based on the number of CRS antenna ports of the servingcell.
 3. The terminal apparatus according to claim 1, wherein thereception circuit is configured to and/or programmed to receive thirdinformation indicating a third ratio between a first ratio of PDSCHenergy per resource element (EPRE) to CRS EPRE of a serving cell and asecond ratio of the PDSCH EPRE to the CRS EPRE of the serving cell, andin the second subframe, an orthogonal frequency division multiplexing(OFDM) symbol corresponding to the first ratio and an OFDM symbolcorresponding to the second ratio are based on the number of CRS antennaports indicated by the second information corresponding to the PDSCH. 4.A communication method used in a terminal apparatus that is configuredto communicate with a base station apparatus, the communication methodcomprising: receiving first information indicating a first subframe inwhich a cell-specific reference signal (CRS) is present, and secondinformation which indicates the number of CRS antenna ports and is usedto determine a resource element to which a physical downlink controlchannel (PDSCH) is mapped, wherein, in a second subframe other than thefirst subframe, a PDSCH transmitted through an antenna port differentfrom a CRS antenna port for a serving cell is mapped to a resourceelement, the resource element being determined based on the number ofCRS antenna ports indicated by the second information corresponding tothe PDSCH.
 5. The communication method according to claim 4, furthercomprising: receiving third information indicating a third ratio betweena first ratio of PDSCH energy per resource element (EPRE) to CRS EPRE ofa serving cell and a second ratio of the PDSCH EPRE to the CRS EPRE ofthe serving cell, wherein, in the second subframe, an orthogonalfrequency division multiplexing (OFDM) symbol corresponding to the firstratio and an OFDM symbol corresponding to the second ratio are based onthe number of CRS antenna ports of the serving cell.
 6. Thecommunication method according to claim 4, further comprising: receivingthird information indicating a third ratio between a first ratio ofPDSCH energy per resource element (EPRE) to CRS EPRE of a serving celland a second ratio of the PDSCH EPRE to the CRS EPRE of the servingcell, wherein, in the second subframe, an orthogonal frequency divisionmultiplexing (OFDM) symbol corresponding to the first ratio and an OFDMsymbol corresponding to the second ratio are based on the number of CRSantenna ports indicated by the second information corresponding to thePDSCH.
 7. A base station apparatus that is configured to communicatewith a terminal apparatus, the base station apparatus comprising: atransmission circuit configured to and/or programmed to transmit firstinformation indicating a first subframe in which a cell-specificreference signal (CRS) is present, and second information whichindicates the number of CRS antenna ports and is used to determine aresource element to which a physical downlink control channel (PDSCH) ismapped, wherein, in a second subframe other than the first subframe, aPDSCH transmitted through an antenna port different from a CRS antennaport for a serving cell is mapped to a resource element, the resourceelement being determined based on the number of CRS antenna portsindicated by the second information corresponding to the PDSCH.
 8. Thebase station apparatus according to claim 7, wherein the transmissioncircuit is configured to and/or programmed to transmit third informationindicating a third ratio between a first ratio of PDSCH energy perresource element (EPRE) to CRS EPRE of a serving cell and a second ratioof the PDSCH EPRE to the CRS EPRE of the serving cell, and in the secondsubframe, an orthogonal frequency division multiplexing (OFDM) symbolcorresponding to the first ratio and an OFDM symbol corresponding to thesecond ratio are based on the number of CRS antenna ports of the servingcell.
 9. The base station apparatus according to claim 7, wherein thetransmission circuit is configured to and/or programmed to transmitthird information indicating a third ratio between a first ratio ofPDSCH energy per resource element (EPRE) to CRS EPRE of a serving celland a second ratio of the PDSCH EPRE to the CRS EPRE of the servingcell, and in the second subframe, an orthogonal frequency divisionmultiplexing (OFDM) symbol corresponding to the first ratio and an OFDMsymbol corresponding to the second ratio are based on the number of CRSantenna ports indicated by the second information corresponding to thePDSCH.
 10. A communication method used in a base station apparatus thatis configured to communicate with a terminal apparatus, thecommunication method comprising: transmitting first informationindicating a first subframe in which a cell-specific reference signal(CRS) is present, and second information which indicates the number ofCRS antenna ports and is used to determine a resource element to which aphysical downlink control channel (PDSCH) is mapped, wherein, in asecond subframe other than the first subframe, a PDSCH transmittedthrough an antenna port different from a CRS antenna port for a servingcell is mapped to a resource element, the resource element beingdetermined based on the number of CRS antenna ports indicated by thesecond information corresponding to the PDSCH.
 11. The communicationmethod according to claim 10, further comprising: transmitting thirdinformation indicating a third ratio between a first ratio of PDSCHenergy per resource element (EPRE) to CRS EPRE of a serving cell and asecond ratio of the PDSCH EPRE to the CRS EPRE of the serving cell,wherein, in the second subframe, an orthogonal frequency divisionmultiplexing (OFDM) symbol corresponding to the first ratio and an OFDMsymbol corresponding to the second ratio are based on the number of CRSantenna ports of the serving cell.
 12. The communication methodaccording to claim 10, further comprising: transmitting thirdinformation indicating a third ratio between a first ratio of PDSCHenergy per resource element (EPRE) to CRS EPRE of a serving cell and asecond ratio of the PDSCH EPRE to the CRS EPRE of the serving cell,wherein, in the second subframe, an orthogonal frequency divisionmultiplexing (OFDM) symbol corresponding to the first ratio and an OFDMsymbol corresponding to the second ratio are based on the number of CRSantenna ports indicated by the second information corresponding to thePDSCH.